Unnamed (northeast of upper Sheep Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu
Other commodities Au
Ore minerals chalcopyrite; malachite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale TK
Quadrangle map, 1:63,360-scale A-5
Latitude 62.136
Longitude -149.262
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,400 feet, approximately 1/2 mile north-northwest of peak 6319 and 0.8 mile northeast of lake 4101. The occurrence is in the SW1/4 sec. 27, T. 24 N., R. 1 E., Seward Meridian. The location is accurate to within 1/4 mile. This is locality 96 of Csejtey and Miller (1978) and Singer and others (1978).

Geologic setting

Geologic description

This occurrence consists of float of Cretaceous or Paleocene tonalite that has vein quartz with pyrite and chalcopyrite, and is stained by malachite (Csejtey and others, 1978; Csejtey and Miller, 1978). A float sample contains 20 parts per million silver, 1 part per million gold, and greater than 20,000 parts per million copper (Miller and others, 1978).
Geologic map unit (-148.61932017764, 62.4999192169584)
Mineral deposit model Porphyry copper-gold (Cox and Singer, 1986; model 20c)
Mineral deposit model number 20c
Age of mineralization Quartz veins in Cretaceous or younger plutonic rocks.
Alteration of deposit Oxidation of copper minerals.

Production and reserves

Workings or exploration Only limited surface sampling by U.S. Geological Survey (Miller and others, 1978).
Indication of production None


MRDS Number A012185


Reporters D. Bickerstaff (U.S. Geological Survey)
Last report date 10/1/2002